Sunday’s monsoon rains brought the Phoenix region treacherous flooding that prompted numerous water rescues and historically low temperatures during the hottest time of the year.

The midday storm flooded roads and washes in parts of Maricopa and Pinal counties, according to the National Weather Service, which issued a flash-flood warning for parts of both counties.

It was the biggest, wettest storm of this year’s monsoon, which began June 15, said meteorologist Mark O’Malley. It covered a wider area and dropped more rain than any other so far, and lifted the total yearly rainfall above Arizona’s average, he said.

As of Sunday, 0.98 inch of rain had fallen in the region, compared with the 0.63 inch that typically falls by July 21, O’Malley said.

At the same time, it was an unusually cool day, with a high of 87 degrees and a low of 74, he said. The average high temperature for the day is 106.

It tied for the second-coolest July 21 on record, O’Malley said. The coolest July 21 was in 1896, with a high of 85 degrees. Highs of 87 degrees on July 21 were also recorded in 1986 and 1913, he said.

“You don’t get too many days like this in Phoenix for the year,” O’Malley said. “This will probably be the only day we get like this.”

Little wind accompanied the precipitation, sparing the region from uprooted trees, downed power lines and other forms of wind-driven destruction, O’Malley said.

“It didn’t create a lot of wind damage, but it created a lot of flooding damage and people being plucked from cars,” he said.

At least nine people were rescued in five municipalities, officials said.

In Pinal County, two 19-year-old men were trapped in a tree near Lost Dutchman State Park until they were rescued by an Arizona Department of Public Safety helicopter and the Pinal County Sheriff’s Office, officials said.

Scottsdale crews utilized rescue swimmers to save a stranded motorist near 83rd Street and Desert Cove Avenue. More than 25 firefighters from Tempe, Phoenix and Scottsdale responded to the scene, Scottsdale Battalion Chief David Folio said.

In a second Scottsdale rescue, crews extricated two people whose vehicle got stuck near Scottsdale Road and Sutton Drive, Folio said.

Some of the worst flooding was reported in Apache Junction, where more than 2 inches of rain swamped roads and washes and carried some vehicles along like boats, according to 12 News live aerial video.

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